Arsenic uptake by two vegetables grown in two soils amended with As-bearing animal manures.
Organoarsenicals are widely used as growth promoters in animal feed, resulting in unabsorbed arsenic (As) left in animal manures. A pot experiment was conducted to investigate the growth and As uptake of amaranth (Amaranthus tricolor Linn, a crop with an axial root system) and water spinach (Ipomoea aquatica Forsk, a crop with a fibrous root system) grown in a paddy soil (PS) and a lateritic red soil (LRS) amended with 2% and 4% (w/w) As-bearing chicken manure and pig manure, respectively. Soils without any fertilizers were the controls. The biomass, As contents and total As uptake of the shoots, As transfer factors (TFs) from roots to shoots and the root/shoot (R/S) ratios of water spinach were significantly higher than those of amaranth (p<0.0015). The biomass, total As uptake and R/S ratios showed significant difference for soil types (p<0.0031). Manure amendments increased the biomass of both vegetables, reduced the As contents in amaranth but increased those in water spinach. The As contents were negatively correlated with the biomass in amaranth, but positive correlation was observed for water spinach. The total As uptake by amaranth was decreased in PS and insignificantly affected in LRS by manure application, but that by water spinach was significantly increased in both soils. We suggest that the higher As uptake by water spinach might be related to its root structure and R/S ratio. Heavy application of As-bearing animal manures should be avoided in water spinach.
Yao
Li-Xian
LX
School of Environmental Science and Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, PR China.
Li
Guo-Liang
GL
Dang
Zhi
Z
He
Zhao-Huan
ZH
Zhou
Chang-Min
CM
Yang
Bao-Mei
BM
D027721:Amaranthus / Q000378:metabolism; D000818:Animals; D001151:Arsenic / Q000378:metabolism*; D002645:Chickens; D005506:Food Contamination / Q000032:analysis*; D027741:Ipomoea / Q000378:metabolism; D008372:Manure / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013552:Swine; D014675:Vegetables / Q000378:metabolism*
D008372:Manure; D012989:Soil Pollutants; D001151:Arsenic